Revit & 3ds Max

[dbaldacchino]

Well,

We just tried a first test to see if linking works and I have to say that it didn't go well at all.

We started by exporting the Revit to a dwg. Then we started a new max file and linked the dwg in it. We were thrilled to see that all the material assignments actually came with it. So we made a few changes to some materials in max and saved the file. We changed a few things and materials in the Revit model, exported it again with the same name as a dwg and from max, we reloaded the linked dwg. All changes were lost and the file reverted back to the original Revit materials. Not good.

Then, something happened and max crashed, so we re-opened it and tried to reload the max file, which was about 7.3MB. The thumbnail shows the model, but once the file is open, there is nothing in it. Link manager is empty, there are no materials....but the file is still over 7MB.

So we redid the linking and saved to a max file yet again. We did not change anything this time, just closed the file and opened it again. Same thing....over 7MB, thumbnail shows model, but the file is empty.

Are we having a bad day or has anyone experienced this before? I thought max was supposed to work seamlessly with linked dwg's, so design can continue in the Revit model, materials, lights etc can be added in max by someone else in a max file with a linked dwg, and once rendering day dawns, the dwg file is reloaded to get the latest geometry and off we go. Am I far from reality?

[hand471037]

Are we having a bad day or has anyone experienced this before? I thought max was supposed to work seamlessly with linked dwg's, so design can continue in the Revit model, materials, lights etc can be added in max by someone else in a max file with a linked dwg, and once rendering day dawns, the dwg file is reloaded to get the latest geometry and off we go. Am I far from reality?

I think you need to look at your file linking options. When you reload the link there are options there for what Max does upon reload, and you have to use the right ones for it to work. This could be where you're going wrong. Check the Max tutorial on the subject, or hopefully someone who's done more of this will pop up and answer your question. I've been learning this too, so... not much of a help other than that.

[dbaldacchino]

Hey np, thanks for your thoughts.

We actually suspected that, but the thing is....we were not even successful in saving a file with a linked dwg. The guy working on max has done this before with other dwg files, but has never seen this happen. So we were attributing this to the exported dwg version from Revit. I'm not sure.

Hopefully someone else will shed some light on this. In the meantime we'll research some more.

[Gene Herring]

David, I am also learning as you guys but have been having fairly good success with a few minor exceptions which I attribute more to the Max side of things. For starters Max 8 handles the translation much more effeciently than Ver.7. It actually has dll files specifically designed to translate Revit based dwg files. There is also a revit import template that you may have to tweak a little to optimize with your files. I have been toying with the link setup for several months now and have not experienced the problems you are reffering to. In the max 8 import template, there are a couple of options on reload (see attached) that specifically deal with retaining max's material definitions or overiding if you change them in Revit. Another pointer is that you stay the Hell away from exporting procedural maps as they come over into max as basic shaders. To optimize this, I have basically created a "common" materials folder of bitmaps that I point both my Revit and max materials to. this insures I am working from the same page. Even if something gets lost in the translation, the saved Max library easily pops up with the same bitmaps optimized for the max environment. Lately I have thrown myself another twist on this entire issue with the inclusion of Vray in the mix. Now I am developing a third "common" library with "Vray" based materials. All three use essentially the same bitmap images, just optimized for the specific rendering environment. (See a couple of samples I posted yesterday in the Gallery).

I am at a total loss why your files are crashing becuase I link and reload several times a day with no problems. I have most likely done it a 100 times the past couple of months with no crashes. something buggy going on there. Not a workflow problem. There are a few nuances though I am working around. You will have to spend a little time setting up your layer export template to make objects a little more granular for easy remap in Max when necessary. Some things are grouped in a common layer in revit that you may want separated more cleanly in max. this can also be saved to several standardized templates that suit your needs.

Also per Jeffs comments, the max help file does get fairly in depth about the linking options and relative pit falls.

My greatest struggle right now is more with getting the UVW image mapping straight in a few areas. This is where the factory needs to do some more work with the translator. Keeping in mind this is more a Max issue than Revit, so I don't expect to see Revit 9 solve it.

hope this helps.

[dbaldacchino]

Thanks for the in-depth reply. We will start again from scratch Monday and see if we can trace the evil. We were stumped when the linked dwg would not show up when we re-opened the max file. Didn't make sense, especially as the file size was still large. Perhaps I'll try a save with audit/compact first for the Revit file and re-export. We might try a simple test with just some walls to understand the nuances and if all fails, there's always the Create Support Request button ;)

Will keep you posted!

[dbaldacchino]

Well, we got one thing to work. I think we had some PC issues, which were causing the file to not show the linked dwg.

We are still having problems though, and I was wondering if anyone could shed some light on it. When we reload the linked dwg in 3ds max (8.0), the materials revert back to what was assigned in Revit. What we can do is to save the max material library and reapply it once the file is reloaded. So we can keep it simple in Revit, and than assign the "fancier" maps etc. to the same Revit material inside max. That works. But if in max, we re-assign a material (say, a brick wall is changed to split face material), then it reverts back to brick once we reload the dwg. Or if a material color for paint in Revit was originally yellow and we change it to red in max, when the linked file is reloaded, it changes back to yellow.

Is this by design? I thought that the max file should remember the changes done to the linked dwg and override Revit's material assignments. Am I thinking wrong? Thanks all!

[hand471037]

Is this by design? I thought that the max file should remember the changes done to the linked dwg and override Revit's material assignments. Am I thinking wrong? Thanks all!

Don't have time to dig for it, but I think there is a setting in the reload link dialog that tells Max whether to keep the scene materials or use the 'new' ones coming in from the reload. You want the former, not the latter, otherwise it will set everything back the way it was.

If I have time later on (or if someone knows off the top of their head) I'll post a more complete answer later...

[dbaldacchino]

Thanks Jeffrey. I'll look into it right away, we only have one copy and it's heavily used so I don't get time to "fiddle" much!

[hand471037]

wait, I think I found it. When you open the File Link Manager, and pick your linked in Revit Project, make certain you've got 'show reload options' checked below prior to clicking on 'reload'. Once you click on reload, you'll get an options window for how Max should reload the Revit Project in. Go to the Advanced Tab, and check the boxes 'Use Scene Material definitions' and 'Use Scene Material Assigments on Reload' and hit OK. Max should now keep it's materials and remember where they were assigned, and not loose them, when the link reloads...

[dbaldacchino]

Well, we had been doing that already, but it still reverted to Revit materials. But, I think we found a solution.

We were not renaming the materials. For instance, Wall_CMU was showing up in Max as such. We just changed the definition (maps, color, etc) and when we reloaded the dwg, the material reverted back to the Revit definition.

So we tried renaming the material to, say, m_Wall_CMU (m for max), and when the model is reloaded, the material stays. So I guess the relinking will sort of override your decision to keep the Max materials if it finds the exact same named material in Revit.

Thanks a LOT for your help!

[hand471037]

Well, we had been doing that already, but it still reverted to Revit materials. But, I think we found a solution.

We were not renaming the materials. For instance, Wall_CMU was showing up in Max as such. We just changed the definition (maps, color, etc) and when we reloaded the dwg, the material reverted back to the Revit definition.

So we tried renaming the material to, say, m_Wall_CMU (m for max), and when the model is reloaded, the material stays. So I guess the relinking will sort of override your decision to keep the Max materials if it finds the exact same named material in Revit.

Thanks a LOT for your help!

No, thank you! I didn't know the naming was important, for I hadn't hit that problem yet. I was 'swapping' materials, not just redefining them, so it was defining a new name anyways for those items. Good to know!

[dbaldacchino]

Haha, that's why you didn't seem to have the "problem" we were having.

We collectively found out how it works, which is good. We're all happy now that our workflow should improve significantly, and is yet another great reason for using Revit over traditional CAD.

[Andre Baros]

One thing which I have found adds a lot of reliability to the linking is to export using shared coordinates instead of project coordinates. This is not the default, and you have to change this every time you export but it seams to be MUCH more reliable for me. Using project coordinates, after several reloads I would notice items moving out of place (sometimes quite radically, as the relinked model would be scattered across space) Using shared coordinates (which are apparently more absolute) I've had zero problems (which I shouldn't say as I'm in the middle of reloading a bunch of files at the moment).

Another thing I do is export each workset separately and the import them in one by one. This way you don't always have to re-export the whole model each time you have a small change. Also if you put each design option on it's own workset (sort of redundant) you can just export those, I take the extra step of importing each option into it's own max file and then linking them back in so that on the max side scene management is much easier.

With Revit and Max we've had a huge jump in the number of projects getting rendered.

[Arnel Aguel]

One thing which I have found adds a lot of reliability to the linking is to export using shared coordinates instead of project coordinates. This is not the default, and you have to change this every time you export but it seams to be MUCH more reliable for me. Using project coordinates, after several reloads I would notice items moving out of place (sometimes quite radically, as the relinked model would be scattered across space) Using shared coordinates (which are apparently more absolute) I've had zero problems (which I shouldn't say as I'm in the middle of reloading a bunch of files at the moment).

This seems to be not Revit problem but viz/max issue if I remember correctly there were some issues about this for DWG files exported from ADT and Revit and file link to viz/max where some elements moved out of place. The work around before was just to hit reload again in the file link manager if you have objects moved out of place.

[dbaldacchino]

We have not noticed anything regarding the shared vs project coordinates issue, but will keep that tip in mind for that dark day when the building explodes in space or weird things start to happen :)

One thing we noticed was that if you have a section box turned on in 3d and your building is cut, the exported dwg will actually contain this exact view. I expected the export to contain the whole model, so I was surprised, and will always make sure to expored a full 3D view to dwg.